Income Taxes - Components of Net Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands |
Dec. 31, 2015 |
Dec. 31, 2014 |
|---|---|---|
| Income Tax Disclosure [Abstract] | ||
| Share based awards compensation | $ 1,502 | $ 1,085 |
| Allowance for returns | 0 | 0 |
| Inventory reserve | 0 | 0 |
| Book accumulated depreciation net of tax | (1,386) | (1,475) |
| Other deferred revenue | 249 | 335 |
| Patents | 1,396 | 1,290 |
| Federal net operating loss | 53,700 | 52,050 |
| State net operating loss | 912 | 1,133 |
| Foreign losses | 2,929 | 2,368 |
| R&D credit carryover | 1,723 | 1,723 |
| Write-up of intangibles | (337) | (443) |
| Other | 162 | 201 |
| Net deferred tax assets | 60,850 | 58,267 |
| Federal | (60,850) | (58,267) |
| Deferred tax asset | $ 0 | $ 0 |